It is well known that vinyl chloride and acrylic latexes are colloidally incompatible when blended together. For instance, mixing two such latexes on equal weight basis results in a highly viscous gel in a matter of minutes, indicating incompatibility. Normally, as little as about 10% of one latex in the other will show incompatibility of the two latexes.
Due to the numerous advantages, it is desirable to be able to blend such latexes whereby the resulting latex blend does not show a substantial increase in viscosity or a tendency to gel. If such latexes could be blended without experiencing the incompatibility problems and without significantly changing physical properties thereof, the cost of the more expensive acrylic latex could be reduced by blending it with the less expensive vinyl chloride latex. Furthermore, by replacing some of the acrylic latex with a vinyl chloride latex, improvements in flame retardancy, water resistance, and abrasion resistance of the dried film could be obtained. Ability to blend a vinyl chloride latex with an acrylic latex should also enable one to adjust other physical properties, such as lowering the film forming temperature by replacing a portion of the harder vinyl chloride latex with the softer acrylic latex.